Plastics are now used in every segment of American business and are found in all aspects of daily life. Carpets are now substantially made of plastics. One problem relating to carpets is what to do with them after their service life is exhausted. Furthermore, since a considerable amount of waste is involved in the process of making carpets, the problem also exists of what to do with it once it is generated. For instance, automobile carpet in most instances has a face of fiber forming polymer such as polyamide and/or a polyester and a backing polymer such as a polyolefin or copolymer thereof. Automotive carpet scrap is generated during the cars' fitting process and as post-consumer waste. During the fitting process, a quantity of carpet remnant is generated as the carpet is formed and cut into various irregular shapes. As a result, millions of pounds of carpet waste are generated every year as part of the automobile manufacturing process. It has been difficult to reuse this carpet scrap in the primary manufacturing process, due to problems with separation, and the like. Furthermore, when an automobile is disposed of after its years of useful life, the carpet installed ends up in the waste stream as post-consumer waste.
Besides the carpet waste generated by automobile manufacturing, carpet waste is also generated during residential and non-residential building construction as well as during renovation. The volume of this carpet scrap generated each year is also expected to continue to increase worldwide. Considerable effort has been devoted to recycling carpet waste. Furthermore, the interest in secondary recycling of carpet or other commingled waste continues to increase due to increasing costs of storage and/or land fill space, more stringent regulations for disposal, and incineration, among other things.
A number of methods have been developed for the recycling of carpet scrap. For example, U.S. Pat. No. 5,852,115 discloses the addition of compatibilizing agents to mixtures of carpet scrap. In particular, carpet scrap mixtures of nylon, polyester, polypropylene, polyethylene, ethylenevinyl acetate (EVA), and filler, were compatibilized with a compatibilizing agent selected from the group of a polypropylene having acrylic acid grafted thereon, a maleic anhydride modified polypropylene, a maleic anhydride modified poly(ethylene-co-vinyl acetate), and a poly(ethylene-co-vinylacetate). Substantially homogeneous thermoplastic blends of the carpet scrap and these compatibilizing agents have produced products possessing very useful properties, for instance, tensile strengths, elongations at break, and hardness. Further improvements have been sought in the field of recycling carpet scrap.